package com.bjc.nio.groupchat;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Scanner;
import java.util.concurrent.TimeUnit;

/**
 * @program: nettypro
 * @description:
 * @author: bjc
 * @create: 2021-09-04 22:17
 */
public class GroupChatClient {

    /**
     * 服务器的ip
     */
    private static final String HOST = "127.0.0.1";

    private static final int PORT = 6667;

    private Selector selector;

    private SocketChannel socketChannel;

    private String username;

    public GroupChatClient() throws IOException {
        selector = Selector.open();
        //连接服务器
        socketChannel = socketChannel.open(new InetSocketAddress(HOST, PORT));
        //设置非阻塞
        socketChannel.configureBlocking(false);
        //将channel注册到selector
        socketChannel.register(selector, SelectionKey.OP_READ);
        //得到username
        username = socketChannel.getLocalAddress().toString().substring(1);
        System.out.println(username + " is ok.....");
    }

    /**
     * 向服务器发送消息
     *
     * @param info
     */
    public void sendInfo(String info) {
        info = username + "说：" + info;
        try {
            socketChannel.write(ByteBuffer.wrap(info.getBytes()));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 读取服务端回复的消息
     */
    public void readInfo() {
        try {
            int readChannels = selector.select();
            if (readChannels > 0) { // 有可以用的通道
                Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();
                while (iterator.hasNext()) {
                    SelectionKey key = iterator.next();
                    if (key.isReadable()) {
                        //得到相关的通道
                        SocketChannel sc = (SocketChannel) key.channel();
                        //得到一个buffer
                        ByteBuffer buffer = ByteBuffer.allocate(1024);
                        //读取
                        sc.read(buffer);
                        //把读取到的缓冲区的数据转成字符串
                        String msg = new String(buffer.array());
                        System.out.println(msg.trim());
                        //防止重复操作
                        iterator.remove();
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws Exception {
        GroupChatClient chatClient = new GroupChatClient();

        new Thread(()->{
            while (true){
                chatClient.readInfo();
                try {
                    TimeUnit.SECONDS.sleep(3L);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();

        //发送数据给服务端
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextLine()){
            String s = scanner.nextLine();
            chatClient.sendInfo(s);
        }
    }
}
